Yao Fu

From Cryogenic to Room Temperature: Advances in DNP-MAS for
Materials Characterization

This presentation highlights recent advances in Dynamic Nuclear
Polarization (DNP)-enhanced solid-state NMR spanning temperatures from
cryogenic (30-100 K) to ambient conditions. At cryogenic temperatures, cross-
effect DNP was applied to a range of material systems, including SiO₂
nanoparticle-polymer composites, conductive mesoporous polymers, and the
metal-organic framework (MOF) UiO-66. In UiO-66, DNP-enhanced NMR
revealed previously unrecognized water-induced structural rearrangements, in
which water molecules reversibly replace coordinating linkers to form
hydrogen-bond-stabilized dangling groups. To overcome limitations associated
with exogenous polarizing agents and low-temperature operation, room-
temperature Overhauser DNP was explored in trityl radical thin films relevant
to OLED technologies. Efficient polarization transfer and site-resolved
measurements of electron delocalization were achieved under ambient
conditions. Together, these studies illustrate the evolution of DNP methodologies
across a broad temperature range and highlight their growing potential for
investigating increasingly complex and technologically relevant material
systems.

8:00 AM California or 11:00 AM Boston or 5:00 PM Paris or 8:30 PM Delhi